Photovoltaic panel circuitry

Abstract

Circuits integrated or integrable with a photovoltaic panel to provide built-in functionality to the photovoltaic panel including safety features such as arc detection and elimination, ground fault detection and elimination, reverse current protection, monitoring of the performance of the photovoltaic panel, transmission of the monitored parameters and theft prevention of the photovoltaic panel. The circuits may avoid power conversion, for instance DC / DC power conversion, may avoid performing maximum power tracking to include a minimum number of components and thereby increase overall reliability.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to United Kingdom Application GB1201506.1 filed Jan. 30, 2012. Benefit of the filing date of this prior application is hereby claimed. This prior application is hereby incorporated by reference in its entirety.BACKGROUND[0002]1. Technical Field[0003]Aspects of the present disclosure relate to distributed power systems, particularly a circuit for integrating with or attaching to a photovoltaic panel.[0004]2. Description of Related Art[0005]A conventional photovoltaic distributed power harvesting system multiple photovoltaic panels are interconnected and connected to an inverter. Various environmental and operational conditions impact the power output of the photovoltaic panels. For example, the solar energy incident, ambient temperature and other factors impact the power extracted from each photovoltaic panel. Dependent on the number and type of panels used, the extracted power may vary widely in the voltag...

AI Technical Summary

Benefits of technology

The patent describes a circuit that can be integrated into a photovoltaic panel to provide additional functions such as safety features, monitoring performance, and theft prevention. The circuit avoids power conversion and performs the necessary functions with a minimum number of components, increasing reliability. The circuit has input and output terminals and a controller that can detect and respond to various malfunctions, such as arcing, ground fault, and excessive voltage or temperature. The circuit can disconnect the photovoltaic panel from the output terminals and bypass the current around the switch and the panel to eliminate the malfunctions. The technical effects of the patent are improved safety and reliability of photovoltaic panels with built-in functionality.

Problems solved by technology

Changes in temperature, solar irradiance and shading, either from near objects such as trees or far objects such as clouds, can cause power losses.

Owners and even professional installers may find it difficult to verify the correct operation of the system.

With time, many more factors, such as aging, dust and dirt collection and panel degradation affect the performance of the solar photovoltaic distributed power system.

Data collected at the inverter may not be sufficient to provide proper monitoring of the operation of the system.

However, a duplex transmission method requires additional transmission lines and complicates the system.

On the other hand, one-way transmission may be prone to collisions and makes it difficult to compare data transmitted from the various sources.

Due to the wide variability of power output of such systems, and the wide range of environmental conditions that affect the power output, the output parameters from the overall system may not be sufficient to verify whether the solar array is operating at peak power production.

Local disturbances, such as faulty installation, improper maintenance, reliability issues and obstructions might cause local power losses which may be difficult to detect from overall monitoring parameters.

Electric arcing can have detrimental effects on electric power distribution systems and electronic equipment.

Arcing may occur in switches, circuit breakers, relay contacts, fuses and poor cable terminations.

If a circuit has enough current and voltage to sustain an arc, the arc can cause damage to equipment such as melting of conductors, destruction of insulation, and fire.

A direct current system may be more prone to arcing than AC systems because of the absence of zero crossing in DC power systems.

However, the cost of photovoltaic panels and their relative ease of theft, might limit their adoption for use in power generation systems.

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